Transcript Use of EpiData (questionnaire design and entry)

Use of EpiData
(questionnaire design and entry)
Jurgita Bagdonaite
Jurmala, Latvia, 2006
Based on EPIET material
Introduction to EpiData
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Data entry and documentation
Free program
Based on EpiInfo
Windows format
No limit on No of observation
(tested with >100.000)
EpiData (I)
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Creating questionnaire
Controlled data entry
Documenting and printing data
Correction of questionnaires, records
Comparing of 2 data files
Importing and exporting data
Simple analysis
EpiData (II)
• Simple surveys – one questionnaire
• Complicated surveys – few questionaires
If there is ID – possible to merge data
EpiData files
• .QES file
– Questionnaire
• .REC file
– Actual data
• .CHK file
– Any defined checks
• Other notes or log files
EpiData workflow
1.Define Data
2.Make Data File
3. Set up Checks
4.Enter Data
5.Document
6.Export Data
Creating Questionnaire
• Define Data
• Can either open .QES file or create one
New questionnaire
• Type in window
• Cut and paste from Word documents
• Preview questionnaire
– (click Make data file > preview data form)
Structure of questionnaire
Three sections:
– Field name (variable)
– Text describing field
– Input definition (number/ letters/ date)
Field name (variable)
• No more than 10 characters
• Begin with a letter
• No spaces or punctuation marks
Field Name (II)
• First word
– Uses first word of line
• Automatic
– EpiData generates
field names based on
question
– Uses first 10 letters
Childquest
Child questionnaire
<Y>
Automatic field names
• Text in curly brackets { } used in
preference
• Common words skipped (what, the, and,
etc.)
• If question starts with number, “N” is
inserted before the number
Automatic field names,
examples
Question:
Field name:
Did you {eat ice cream}
What is your name?
2. Age
EATICECREAM
ISYOURNAME
N2AGE
Variable type
• Define variables using “Pick List” or “Code
writer”
• Choose type of variable:
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Numeric
Text
Date
Soundex
Boolean (Yes/No)
Autonumber
Text variables
• Information of text and/or numbers
• Holding information (e.g. names, addresses)
• UPPER CASE
– Can only hold upper case (capital) letters
– Lower case variable automatically converted into
upper case text (ex: Egypt converted into EGYPT)
• No mathematical operations
• Length (How many characters)
• <_>
Numeric variables
• Numerical information
• Hold integers (whole numbers) or numbers
with a decimal point
• Length (digits, decimals after the comma)
• <#>, <##.#>
Other variables
• Boolean variables (s. logical variables s. YES/NO
variables)
– only two possible answers: Yes or No
– <Y>
• Date variables:
– Hold information on dates
– Data in american <MM/DD/YYYY>
– European <DD/MM/YYYY>
• Soundex:
– Coding of words (anonymous, eg. A-123)
– Code to limit orthographic errors (eg. Rome and Roma)
– <S >
System variables
• Values generated automatically
• Today date: date of the data entry
– <Today-dmy>
– <Today-mdy>
• Auto identification number: Counts the
records entered
– <IDNUM>
Save Questionnaire
• Preview data
• Save questionnaire
– Creates .QES file
• Create Data file
– Click Make Data file button > Make Data file
– Creates .REC file
• Questionnaire and Data file ready
• But……
Errors in data entry
• Tranposition (ex: 39 becomes 93)
• Copying errors (0 copy as an “o” letter)
• Consistency errors: two or more responses
are contradictory (sex: man, pregnancy=Yes)
• Range errors: answers outside of probable or
possible values (ex: heigh = 3 metres)
Preventing errors
• Standardised and previously tested questionnaire
• Training the interviewers and data entry clerck
• Checking and validating paper forms of the
questionnaires
• Checking during the data entry (Check module EpiData)
• Validation: entering twice data by different operators
• Checking after data entry (Analysis module Epi-Info)
Checks (I)
• Reduce errors in input
• Checks help with data entry
• Many different types
• Examples:
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Limit entry of numbers to specific range
Forcing entry to be made in field
Conditional jumps
Copying the data from the previous record
Help messages
Conditional operations (ex if….then operations)
Checks (II)
• Once Data file is created:
• Click Checks button > choose .REC file
Checks (III)
• Range, legal:
– 1-3, 9
– First range then individual numbers
– Tallinn, Riga, Vilnius
– Fixing only min or max value
• -INF-5 (all numbers inferior or equal 5)
• 0-INF (all positive numbers superior or equal to 0)
• Jumps:
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Field: AGEYEARS
0>AGEMONTHS
0>AGEMONTHS, 1>ADDRESS
1>END
• MustEnter:
– Data must be entered in Field
Checks (IV)
• Repeat:
– Show data from previous record
• Value Label
– Add text to explain values
– Click + to add label
– Format as shown
– Press F9 during data entry
to see labels
Data Entry (I)
• Click Enter data button
> choose .REC file
• Dates:
– 15/5/2006 – type 150506 or 15/5/06
• Value Labels:
– Press F9 to view
Data Entry (II)
• Record navigation:
• Delete records:
– Click cross to delete
– Record marked for deletion, but can be
recovered
Document Tools
• File Structure
• Data entry notes ( .NOT file)
– Use to write comments during data entry eg: difficult to read
handwriting etc
• View Data
• List Data
• Codebook
– Basic descriptive statistics on all variables
• Validate duplicate files
– Check consistency after double entry
Export to other programs
• Click Export data button
• Choose program
• Including Excel, Stata, SPSS
• For Epi-info open .REC file directly
References
• Lauritsen JM & Bruus M. EpiData (version 3.1). A
comprehensive tool for validated entry and
documentation of data. The EpiData Association,
Odense Denmark, 2004.
• Lauritsen JM, Bruus M. EpiTour - An introduction to
validated dataentry and documentation of data by use of
EpiData. The EpiData Association, Odense Denmark,
2005.
www.epidata.dk